2005 Ford Shelby GR1 Concept with Aluminum Body review and pictures

The Ford Shelby GR-1 concept springs from a long line of Ford performance project cars and quickly establishes itself as one of the most contemporary and dramatic front-engine, two-seat, fastback supercars. This running prototype reaches closer to reality with a 605-horsepower, 390-cubic-inch all-aluminum V-10 engine, a road-tested version of the Ford GT suspension and a stunning new polished-aluminum body.

Sensuous, perfectly proportioned and wholly modern, this show car builds on the success of the Ford Shelby Cobra concept - the 2004 North American International Auto Show (NAIAS) "Best in Show" winner - and reinforces Ford's continued commitment to performance.

The Shelby GR-1 concept's name pays tribute to both a performance great and "Group Racing." This uniquely emotional American sports car design represents Ford's continued desire to include a high-end, limited-production specialist supercar in its lineup. Initially unveiled as a design exercise at the Pebble Beach Concours d'Elegance in August, the Ford Shelby GR-1 concept is a sports car salute to "performance art."

The Shelby GR-1 concept combines modern sculptured surfaces and a sleek muscular fastback design. All of the sophisticated mechanicals of this extraordinary coupe are wrapped in a sleek, muscular aluminum skin left bare and polished bright. The result is a forward-looking supercar with attention-grabbing Ford presence and Carroll Shelby inspiration.

A REALITY-BASED CONCEPT

Much like the original Ford GT and last year's Shelby Cobra concept vehicles, the Shelby GR-1 was intended to be a fully engineered, production-feasible roadgoing, drivable project vehicle.

"With the Ford GT and Ford Shelby Cobra concept, we have a tremendous amount of experience quickly building high-performance cars, like the Shelby GR-1, with world-class performance," says Phil Martens, group vice president, Product Creation. "Our goal this time around was not to create the ultimate top-speed, high-performance sports car. Really, we intended to strike a better balance of design, capability and usability that might appeal to someone considering a Ferrari 575M Maranello."

The Shelby GR-1 starts with a modified version of the aluminum chassis from the rear-engine Ford GT. The bulk of the rear structure is made from slightly modified Ford GT components, including the massive trellis-like, cast-aluminum suspension nodes, the rear rails and bumper beam, a major cross-member and the brackets used to mount the transmission.

The center portion of the spaceframe also borrows liberally from the Ford GT as major aluminum extrusions are based heavily on existing pieces. At the front of the coupe, the team incorporated extruded main rails, a steering rack cross-member, crash-management sections and the bumper beam from the Ford GT.

"Building a concept car with this level of sophistication is much easier when you start with a world-class supercar like the Ford GT," says Martens. "This commonality and re-use goes hand-in-hand with our speed and cost efficiency, promising the Ford GT's bang-for-the-buck equation if the Shelby GR-1 goes to production."

Overall, the Ford Shelby GR-1 concept is more than two feet shorter than the Ford GT, with a wheelbase nearly seven inches shorter. The track width has been reduced by more than an inch. That the concept car and the GT share any parts at all is a testimony to the flexibility of the space frame design and the creativity of the chassis team.

SHAPELY EXTERIOR

The Ford Shelby GR-1 is a sinewy, athletic design with a long hood that blends seamlessly into the teardrop-shaped cabin with a fastback roofline and falling upper fender line. The car looks as if it is in motion, even when it is standing still.

The optimized wheel arches and compact overhangs define the striking stance while the strong shoulder line and smooth, taut surfaces express the car's graceful yet athletic nature. The polished aluminum body panels further express the highly sculptured surfaces and define the emotional proportions in dramatic fashion.

The front of the Shelby GR-1 concept is dominated by an air-intake aperture and airflow splitter, directing cool air into the engine bay and wheel wells, while air vents on the upper surface of the hood exhaust hot air from the radiator. Additional intakes and vents perforate the body side to ensure cooling throughout.

The front corners of the Shelby GR-1 are dominated by substantial front wheel wells housing 19-inch wheels and tires and trapezoidal High Intensity Solid State (HISS) headlamps that float above the wheel arches. This highly technical lighting package provides powerful illumination in a very compact package, allowing freedom of design without sacrificing nighttime driving visibility.

In the rear, a distinctive Kamm tail tapers to improve wind drag and features integrated transmission cooler outlets and a ground-effects venturi. It is further defined by a strong concave section and bold vertical taillamps.

The Shelby GR-1 concept sits on 19-inch, 12-spoke milled aluminum wheels and features Goodyear 275/40R-19 tires in the front and 345/35R-19 tires in the rear, mated with the unique Tire IQ™ system, which allows the driver to monitor precise tire performance.

The graceful upward glide of the doors leads into the race-inspired interior that features seats with carbon shells and fixed backs. The carbon shells are connected directly to the sill and tunnel via lightweight aluminum spaceframe attachments and can be adjusted fore and aft by way of an accessible pull ring on the seat cushions' leading edge. The seats incorporate removable Alcantara comfort inserts that are individually tailored to the occupants' body type.

Interior cabin technology focuses on driver comfort, enjoyment and entertainment. The instrument panel sports a full complement of analog gauges, including a combination analog tachometer with floating watch-like elements and digital speedometer. The tachometer housing has integrated air registers and an additional Noise Reduction Technology (NRT) output speaker.

The centrally mounted Tire IQ™ display is a sophisticated driver's aid designed to inform, warn and even entertain. The Tire IQ™ system provides the driver and passenger with an animation of vital tire temperature and pressure statistics (via sensors in the tire), along with other key vehicle dynamics such as cornering G forces (via an onboard accelerometer).

The center console features integrated toggles that control the fuel pump, ignition, windows, hood and rear-glass release. The race-inspired push-button starter and "baseball grip" gear knob are situated ahead of the parking brake, which has been incorporated into the tunnel armrest. The quick-release steering wheel has integrated headlamp, wiper and direction indicator controls.

Special attention has been paid to noise reduction on the interior. The rear hatch stowage compartment features a removable MP3/Amp and NRT console, while audio input, output and recording speakers are integrated into the headrest protection wings on each seat. The speakers can provide a combination of the following:

The MP3/AMP/NRT functions can be interfaced through the Tire IQ™ display through a joystick controller.

Throughout the interior, the leather trim is in slate gray, with color-matched perforated Alcantara leather featured on touch zones such as the gear knob, parking brake, steering wheel, door inserts, and instrument/Tire IQ™ binnacles. Functional zones such as dials, door release and center console switchgear have been finished in a combination of anodized gunmetal finishes.

Ambient cabin lighting is neatly packaged behind the central headlining panel; an indirect blue glow appears around the periphery offset of the panel. The headliner and upper doorframes are trimmed with a woven aluminum-metalized fabric that lightens the interior ambiance and heightens the slate grey tones of the leather and Alcantara trim. The dark gunmetal-gray flooring also is trimmed in the hard-wearing metalized fabric.

PROVEN CHASSIS COMPONENTS

From the outset, the Shelby GR-1 concept team intended the concept to perform at supercar levels but with a more "mature" feel biased a little more toward driver comfort than the Ford GT - widely noted for its balance of dynamics and road manners - and last year's Ford Shelby Cobra concept.

They started by attaching massive 19-inch wheels and tires using the Ford GT suspension system with a few modifications to accommodate the increased weight of a front-engine setup. The new Ford GT earns praise for its combination of agility, grip and easy-to-drive character, a reflection of its sophisticated suspension design and the expertise of its chassis engineers. The Ford Shelby GR-1 concept applies the best of the GT suspension to a supercar with different performance intentions.

"The biggest difference between the GR-1 concept and our past efforts is the emphasis on overall driver comfort," says Manfred Rumpel, manager, Ford Advanced Product Creation. "That extends all the way to the compliant yet high-performing capability we built into the suspension."

DESIGNED-IN SUSPENSION COMPLIANCE

A double-wishbone suspension design with unequal-length aluminum control arms, coil-over monotube shocks and stabilizer bars is used front and rear. The upper control arms are identical at all four wheels and are made with an advanced rheo-cast process that allows the complexity of form associated with casting while retaining the strength of forging. The metal, heated to just below its melting point, is the consistency of butter when it is injected into a mold at high pressure. Pressure is maintained as the part cures, preventing porosity in the final product for exceptional strength.

The steering rack also is borrowed from the Ford GT, with a few modifications. The steering, like the Ford GT's, draws on Ford's global driving dynamics DNA introduced with the Ford Focus' industry-leading steering column featuring light efforts, low friction and high stiffness. Braces between the front shock towers and below the isolated engine mounts improve torsional rigidity and aid steering response.

SUPERCAR POWERTRAIN

The heart of any supercar is its engine, and the Ford Shelby GR-1 concept does not disappoint.

Inspired by the biggest, baddest engine of them all - the renowned 427 - Ford engineers created a new aluminum-block V-10 to power last year's Ford Shelby Cobra concept. This 390 cubic inch, 6.4-liter engine, reprised for service in the Shelby GR-1 concept, is adapted from Ford's MOD engine family. It delivers the rush of raw power - with 605 horsepower and 501 foot-pounds of torque - associated with that big 1960s V-8 powerplant without the aid of supercharging or turbocharging.

This combination of brute force and thorough engineering has created a rarity in the world of auto shows - a concept car that can actually do, rather than merely promise, 0-60 in under four seconds, and would easily exceed 200 mph if not electronically limited.

"After I drove last year's Cobra concept, I knew we had a winner in the 6.4-liter V-10," says Carroll Shelby, renowned race driver and consultant on the Ford Shelby GR-1 concept. "We decided to transplant that engine directly into the GR-1 with practically no changes, right down to the rear-mounted transmission, which really helps the weight distribution."

For approximately three years, the Ford powertrain team has been working on an all-aluminum V-10 targeted at ultimate, naturally aspirated performance. When they bolted this modern-day big-block into a Mustang chassis for evaluation, it only took one drive to confirm its potential.

"When we found out there was yet another concept car with the Shelby name on it, we knew it begged for this engine," says Graham Hoare, director, Ford Research and Advanced Engineering. "Although it's not yet ready for production, we've reached a credible engineering level for such a serious concept car - and it has a modern soul that matches the Shelby mission."

ADVANCED TRANSMISSION

While the Ford Shelby GR-1 concept shares a significant amount of technology with the Ford GT and the Shelby Cobra concept, the team met several unique engineering challenges head-on.

First, the six-speed manual transmission had to be packaged in a way that would not compromise the occupant footwells. "One of the unique solutions we delivered for the GR-1 concept was the design, engineering and development of a torque-tube driveline, which allows placement of the transmission in the rear of the car behind the occupant zones," says Rumpel.

The rear-mounted six-speed transaxle is identical to the high-performance unit in the Ford GT, with an integral limited-slip differential to drive the rear wheels. Based on the engine's 7,500-rpm redline and the wide drive ratios, this Ford Shelby GR-1 concept has a theoretical top speed of around 200 mph, although it's electronically limited - for now.

The transaxle application was necessitated by the desire to fit such a large engine into a compact coupe while leaving enough room for the driver's legs and feet. With a conventional transmission mated to the back of the engine, the tradeoff between hood length and passenger room often makes for a cramped footwell and dramatically offset pedals.

Mounting the transmission in the rear helped to more evenly distribute the vehicle's weight and increased the footwell area from 16.5 inches to 21.7 inches, resulting in almost three inches more legroom than in similar performance vehicles.

The legroom-saving torque-tube driveshaft runs at engine speed, considerably faster than typical driveshafts mounted to rear of the transmission. The spinning inner shaft is supported within a stationary outer tube that stabilizes the engine and transmission in bending and in torsion. The inner shaft taps crankshaft torque via a twin-disc, small-diameter clutch mounted at the rear of the engine.

Computer-aided design was essential in helping the first prototype come together smoothly.

"Because they spin so much faster than driveshafts, these torque tubes can be a challenge to execute properly in terms of vibration," says Rumpel. "Using our electronic tools, we optimized the location of the driveshaft support bearings, and it ran smoothly on the very first try. This type of modern engineering tool gives us a development advantage that pioneers like Carroll Shelby could only dream about."

The battery was also relocated to the rear of the vehicle, deep inside the luggage compartment, further aiding vehicle weight distribution and better shielding the battery package from the intense heat of the engine compartment. A new cooling system, evolved from the Shelby Cobra concept, includes a unique hood with twin portals to feed air into the engine compartment.From the outset, the GR-1 project team intended the concept to perform at supercar levels, but with a more mature feel biased a little more toward driver comfort than the Ford GT - widely noted for its balance of dynamics and road manners - and last year's Ford Shelby Cobra concept.

They started by attaching massive 19-inch wheels and tires using the Ford GT suspension system with a few modifications to accommodate the increased weight of a front-engine setup.

The new Ford GT earns praise for its combination of agility, grip and easy-to-drive character, a reflection of its sophisticated suspension design and the expertise of its chassis engineers. The Ford Shelby GR-1 concept applies the best of the GT suspension to a supercar with different performance intentions.

POWERFUL BRAKES

With more than 600 horsepower available at the throttle pedal, the brake pedal had to be equally potent. The team set braking distance targets comparable with today's best supercars, and turned to the Ford GT braking system for suitable components.

Brembo "monoblock" one-piece aluminum brake calipers with four pistons each grab cross-drilled, vented discs at all four wheels. The discs are a massive 14 inches in front and 13.2 inches in the rear, for fade-free stopping power. Brake balance is biased slightly to the front wheels to aid stability.

For packaging reasons, the team devised a novel offset actuation linkage for the brake booster and master cylinder, so the brake pedal can be placed in a normal position even though its hardware is off to the side of the engine bay. The kinematic linkage concept for the remote booster actuation was an idea borrowed from the European Ford Mondeo.

"The unique remote booster had to be just right so you can slow the car in a linear and proportional way. This means the pedal effort and travel are proportional to the vehicle deceleration rate, which is especially important in high-performance sports cars," said Rumpel.

The one-piece, 12-spoke BBS wheels are fitted with Goodyear Z-rated racing slicks. The fronts are 275/40R-19 while the rears are 345/35R-19.

"The ultimate litmus test for an engineer is in the hardware. You can do all the CAD work and virtual work that you want, but it really doesn't mean very much until you build it and drive it and show you've delivered the product as planned."- Mark Bergdahl, Supervisor, Chassis and Powertrain Systems Architecture, Ford Advanced Product Creation

The key to occupant safety in a vehicle begins with a strong, solid structure. While weight and vehicle mass have long been considered an advantage for crash safety, neither are desired attributes in a high-performance supercar. Thankfully, the use of modern materials and computer-aided engineering have provided the Ford Shelby GR-1 concept with a spaceframe that is both lightweight and rigid.

The underpinnings of the Shelby GR-1 concept start with a modified version of the aluminum chassis from the rear-engined Ford GT. The bulk of the rear structure is made from slightly modified Ford GT components, including the large, trellis-like cast aluminum suspension nodes, the rear rails and bumper beam, the major cross-member and the brackets that are used to mount the transmission.

The center portion of the spaceframe also borrows liberally from the Ford GT, as the major aluminum extrusions used in the Shelby GR-1 are based heavily on existing pieces. At the front of the coupe, the team incorporated extruded main rails, a steering rack cross-member, special crash-management sections and the bumper beam from the Ford GT.

"Building a concept car with this level of sophistication is much easier when you start with a world-class supercar like the Ford GT," says Phil Martens, group vice president, Product Creation. "This commonality and re-use goes hand-in-hand with our speed and cost efficiency, promising the Ford GT's bang-for-the-buck equation if the Shelby GR-1 goes to production."

HIGH-PERFORMANCE CARS NEED HIGH-PERFORMANCE HEADLAMPS

Driving an exotic, high-performance car at night can be challenging if the vehicle's headlamps can't keep up with the speed of the vehicle. It's a fact that more powerful lighting is a must if spirited nighttime driving is to be done safely in a supercar. To that end, the Shelby GR-1 concept employs a lighting system that is not only more intense, but also more compact than typical headlamps.

The front corners of the Shelby GR-1 are dominated by substantial front wheel wells housing 19-inch wheels and tires and trapezoidal High Intensity Solid State (HISS) headlamps that float above the wheel arches. This highly technical lighting package provides a brighter, more powerful light beam in a very compact package, allowing freedom of design without sacrificing nighttime driving visibility.

TIRES THAT "TALK" TO YOU

No matter how much power and handling ability is built into a supercar, all of the vehicle's performance potential has to be delivered to the pavement through its tires. A driver who knows that all four tires are performing within safe limits can wring the most potential out of the vehicle.

The Shelby GR-1 concept sits on 19-inch, 12-spoke milled aluminum wheels and features Goodyear 275/40R-19 high-performance tires in the front and 345/35R-19 tires in the rear - but all four come equipped with Goodyear's unique Tire IQ™ system that allows the driver to monitor precise information on tire temperature and pressure as well as other key vehicle dynamics such as cornering G forces. The centrally mounted Tire IQ™ display is a sophisticated driver's aid designed to inform about tire conditions, warn of low pressure or impending deflation - even entertain by supplying performance data. The Tire IQ™ readout gives the driver and passenger an animation of vital tire temperature and pressure statistics through sensors in the tire, along with other key vehicle dynamics such as cornering G forces through an onboard accelerometer.

DREAM TEAM II

Following the "Dream Team" that developed the Ford GT, the Shelby GR-1 group became known as "Dream Team II." Like the Ford GT project team, it included key suppliers in a fully integrated effort.

Those suppliers included Aria, in California, the body exterior and interior builder; Techno Sports, the running chassis builder; tire supplier Goodyear, who also formed a joint effort with Siemens VDO to develop the Tire IQ™ system; Metro Technologies, builder of the aluminum spaceframe; Sparco of Italy, who provided seats, steering wheel and foot pedals; Stewart Warner Performance, supplier of the instrument cluster gauges; ZF of Germany, who provided the steering gear and pump; and Superform Aluminum, a UK-based company with a subsidiary in California, who produced the body panels using the same process that was used on the Ford GT.

"We actually did tools and dies to form these exterior aluminum body panels using the production process," Bergdahl pointed out.

In fact, the team applied Ford's Product Development System (FPDS), which defines tasks and deliverables for production vehicle programs, but has never before been applied to a show car. This meant that production level processes for engineering, design, parts procurement and ordering were used early in the development of the GR-1 show car to produce a very high quality product.

The team believed their production-feasible approach made sense, because right from the beginning they knew that limited-volume production was a possibility. They believe their approach has allowed them to shave a full year off the time it would take to put the GR-1 into production.

VIRTUAL REALITY

Virtual analysis tools, including computer-aided engineering (CAE) and computer-aided design (CAD), were used extensively in the Ford Shelby GR-1 project. These tools, which are continually becoming more refined and accurate, helped achieve time savings and cost savings, and what Bergdahl refers to as "first-run capability."

"With a show car, you have to get it right the first time," he says. "Your sample size is one, and you have no second chances given the compressed timeline on a show car. So CAE and CAD were instrumental in the success of this program, and allowed us to achieve the five-month timing."

The GR-1 team used CAE tools for vehicle dynamics simulations and computational fluid dynamics analyses. They did finite element structural analyses, most notably on the aluminum space frame, and also chassis elasto-kinematic analysis, looking at how the suspension performs under different loads and in different wheel travel situations.

The team used CAD to do extensive 3D packaging work, which allowed them to achieve a very high level of production-representative integration for such primary systems as the chassis, powertrain, braking system, suspension, and the fuel, electrical and climate control systems. When it came to building the hardware, everything fit together just the way it was planned.

"Our hardware fabrication was based on manufacturing tolerance blueprints," Bergdahl says, "and ultimately we did a complete vehicle build. If you just look at the running chassis, you can tell there is something special about this one. Everything looks like it's in the right place, where it should be. Things are nicely integrated, and typically that does not happen on a show car."

QUALITY OF EXECUTION

The Ford Shelby GR-1's extremely high level of component fabrication and build quality was the most satisfying result for the engineering team.

"The ultimate litmus test for an engineer is in the hardware," Bergdahl says. "You can do all the CAD work and virtual work that you want, but it really doesn't mean very much until you build it and drive it and show you've delivered the product as planned. Everybody on our team deserves a lot of credit for achieving that level of hardware quality on a show car."

For this reality based concept car, the ultimate test was a session at Ford's Michigan Proving Grounds. The team spent several days doing a lot of dynamic vehicle development, including shock, stabilizer bar and spring tuning, and a variety of testing and development work to make sure they had a competent driver's car that would handle well and be safe to drive at high speeds on a test track. That puts the GR-1 approximately a year ahead of where the Ford GT was at show car time.

Asked about their ultimate measure of success for this project, the team is unanimous: "Production approval!"

And this car, more than any other concept car Ford has ever done, is ready and several steps ahead if production becomes a reality.

FORD & SHELBY: Together again

Carroll Shelby didn't enter his first automobile race - a quarter-mile drag meet - until he was nearly 30 years old. But the hot rod Shelby drove to the finish line that day in 1952 was powered by a Ford V-8.

More than a half-century later, Shelby is one of the most recognized names in performance car and racing history and is back in the Ford family producing concept and production performance cars and trucks.

"Carroll's input is reflected in the performance underpinnings of this concept. I see the Ford Shelby GR-1 concept as a gift to Carroll. We took the chassis he helped create and put this fantastic body on it."- J Mays, Group Vice President of Design and Chief Creative Officer

Shelby's first Ford derivatives were the legendary Cobras and Shelby Mustangs of the 1960s. Today, he is one of the key collaborators on the "Dream Team" that built the 2005 Ford GT and the Ford Shelby Cobra and Shelby GR-1 concept vehicles. He recently announced that his specialty car company will produce a limited-edition Shelby Ford Expedition for sale through select Ford dealers in 2005.

For its part, Ford began to stoke the passions of enthusiasts again by unveiling the all-new, all-modern Ford Shelby GR-1 concept car at the 2004 Pebble Beach Concours d'Elegance, signaling more excitement in the future for Ford and Shelby.

"Carroll's input is reflected in the performance underpinnings of this concept," says J Mays, group vice president of Design and chief creative officer. "I see the Ford Shelby GR-1 concept as a gift to Carroll. We took the chassis he helped create and put this fantastic body on it."

THE LEGEND BEGINS

Shelby may have started late, but he was a winner from the beginning. Just two years into his driving career, Aston Martin's racing manager, John Wyer, recruited him to co-drive a DB3 at Sebring. Within months, the chicken farmer from Texas was mixing it up with the likes of Juan-Manuel Fangio, Phil Hill and Paul Frere. He won Europe's prestigious 24-hour endurance race at Le Mans in 1959, driving an Aston Martin DBR1 with Roy Salvadori.

Early in 1962 Shelby drove his second Ford-powered race car. It was the first mockup for the Cobra, Shelby's now-legendary marriage of a lightweight British roadster body with a small-block Ford V-8. By January 1963, he had homologated the car under the FIA's GT Group III class, and that month a Cobra won its first race, beating a field of Corvette Stingrays at Riverside, California.

In January 1965, Ford hired Shelby to lend his expertise to the GT40 campaign. Three cars had run the 1964 24 Hours of Le Mans, but none of them finished. Shelby began work on installing the more reliable 7-liter stock-car engine in what would be known later as the GT40 Mark II. It proved to be considerably faster than the Mark I, and, although 1965 was another unsuccessful year at Le Mans, GT40 had become, in just two seasons, a strong contender.

Ford and Shelby tested the GT40 Mark II extensively - both in the wind tunnel and on a special dynamometer that simulated a 48-hour run of the Le Mans circuit. At the start of the 1966 season, GT40 began a four-year domination of endurance racing.

While Ford and Shelby took on Ferrari at Le Mans, they fought Corvette at home. The first effort was the legendary Shelby Cobra, a Ford-powered and Shelby-engineered derivative of the AC Ace. Production of the vehicle, which had a tremendous weight advantage over the Corvette, began in June 1962 and continued through March 1967.

THE SHELBY MUSTANG

In August 1964, Ford asked Carroll Shelby to develop a street-legal, high-performance Mustang to compete against the Corvette in SCCA B-production road racing. Shelby-American, Carroll Shelby's Californian racing shop, completed its first Mustang GT350 by September.

The 1965 Shelby Mustang GT350 was a fastback production model with a functional scoop in its fiberglass hood and 306 horsepower from the 289-cubic-inch V-8 underneath - an increase of 35 horsepower over the stock Ford engine. Suspension upgrades included a larger front stabilizer bar, Koni shocks and rear traction bars. Other race-ready features included competition safety belts, a large oil-pressure gauge, tachometer and a trunk-mounted battery. It sold for $4,000 and was instantly recognizable by its Wimbledon White paint and blue GT350 side stripes along the rocker panels.

For 1966, the GT350 was offered in white, red, black, green and blue, and Hertz purchased nearly 1,000 special 1966 GT350H weekend "rent-a-racer" models. In the 1967 model year, the Shelby Mustangs sported unique fiberglass bodywork that extended the front end with an aggressive dual scoop and finished the trunk lid with an integrated spoiler.

But most important in 1967 was the new GT500, a big-block version with 355 horsepower. More than 2,000 of those 428-cubic-inch Mustangs were delivered in the first model year.

1968 was the first year the name "Cobra" was officially used on a Shelby Mustang. That year, a convertible body style also became available. Although the Shelby Cobra GT350 was essentially unchanged, later GT500s were powered by the new "Cobra Jet" 428 engine and thus became the GT500KR, for King of the Road.

For 1969, the penultimate year of the Shelby Mustang, the engine choices included the optional 351 Ram Air engine, and the bodywork incorporated a total of nine scoops - five on the hood, one at the front of each fender and one on each quarter panel. In 1970, with sales slowing, the final Shelby Mustangs built for 1969 were updated to 1970 specifications and sold, ending the famed run.

KEY MOMENTS IN THE HISTORY OF FORD AND CARROL SHELBY

January 1952: Carroll Shelby enters first race at the wheel of a Ford-powered hot rod.

February 1962: Shelby tests his first Ford-powered AC 260 Roadster - the car that would become the Shelby Cobra.